Liquid door-check.



T; MOONEY.

LIQUID DOOR CHECK.

APBLIOATION FILED AUG. 21, 1912.

11,067,61 Patented July 15,1913.

2 SHEETSSHEET 1. I

- 26 I I 50 20 J y 28 29 27 57 UNITED STATES PATENT GBFTCE.

THOMAS MOONEY, OF DOUGLASTON, NEW YORK.

LIQUID DOOR-CHECK.

Specification of Letters Patent.

Patented Jul 15, 1913.

Application filed August 21, 1912. Serial No. 716,180.

liquid through a restricted passage.

One object of the invention is to provide a mechanism that will move the door rapidly during the greater part of the closing move-.

ment; which will then check the movement to prevent slamming; and which will offer no resistance to the latching of the door at the time it is almost wholly closed. I

Another object is so to construct such mechanism that the changes from quick to slow movement of the door may take place without great or undue shock upon the device.

Still another object is the provision of means to prevent the leaking or escape of the liquid used in the structure; and still other objects will appear in the following description and claims.

In the drawings, Figure 1 is a plan view of the device attached to a door; Fig. 2 is a sectional elevation showing the position of parts when the door is closed; Fig. 3 is a similar view showing the position of parts with the door open; Fig. 4 is an elevation of the piston; and Fig. 5 is a sectional elevation of the cylinder in which the piston works, somewhat modified.

' Referring to the drawings, the improved mechanism 15 shown equipped with the usual devices for attaching it to the door and door frame, 1 being the main casing;

2 the cover plate, 3 a sleeve carrying the spring tension head 4, and surrounding shaft 5, the shaft being squared at 6 to re ceive-theend of operating lever 7 which in turn is connected to the adjustable arm 8 attached to the door frame. The spring chamber 9 has attached to it the outer end. of spring 10, the inner end of which is attached at 11 to the sleeve 3. A locking piece 12 is movable upon lever 7 andserves to hold the lever 7 in fixed relation with the tension head 4;. All ofthis mechanism is similar to that provided in well known constructions.

Two very desirable features in a device of this character are that the door should be permitted to close quickly during the greater part of its movement, and that the checking of the door'when nearly closed should not be so sudden that a heavy shock will be applied to the mechanism. These features are secured by the following mechanism: The shaft 5 is carried from the spring chamber 9 through .a partition 14- of the casing and a cap 15 screwed into the partition, the letter carrying a stuffing box through which the shaft passes, and'a-collar 17 upon the shaft aiding to make a liquid "tight seal. The lower part of the casing is divided into two chambers by a cylinder 18 inclosing a position 22, and a partition 20, the upper chamber 13 belng an overflow chamber, and the lower, 21, a pressure chain-- her. The cylinder is internally threaded with multiple threads of coarse pitch 19, 19,

and the piston. is externally threaded in the same way. The piston further is cored out to receive the lower end of shaft 5 and is fitted with a pin 23 engaging a slot-.241 located in the shaft. A suitable liquid, such as glycerin, alcohol and water, or oil, is con-' By this COIlStlllCtlQh" tained in the casing. the rotation of shaft 5 causes the rotation of the piston, and the rotation of the piston causes it to move downwardly in the cylv inder 18, this movement being permitted by the pin and slot connection 23, 24;, with V ward, and during the first part of the move- I ment the liquid is free to flow through the ports 30, 31, so that little resistance is offered to the quick closing of the door during the greater part of its travel; but, as shown in Fig. 2, when these ports are out off by the piston 22 acting as a valve, the easy movement of the liquid is prevented and a check is given to the movement ofthe door. This cut-0E operat: so quickly that a severe shock would be i iparted'to the de .vice were it'not for the special provision iii made to eliminate it. In the present instance this takes the form of a tapered thread either on the lower end of the piston, as shown at 36 in Fig. 4:, or onthe lower end of the cylinder, as shown at 37' ment after the ports 30,. 31 are entirely cut off, as the door is not then wholly closed, and other means are providedto permit the v flow of the liquid. These means include. a

mechanisms of this by-pass 32 in the partition 20 controlled by an adjustable valvestem 33 having a stufling' box and gland 34, 35. It will be noticed that this arrangement permits a further movement of the door, but a very slow one, the retardation at this point belng to prevent the slamming of the door. By this time also the door spring 10 has lost much of its power, and the door having little or no remaining momentum, it is necessary to provide means to withdraw the resistance still oifered by the check in order that there may be sufiicient power available to close the door fully against the pressure of the latch. This means is shown in Fig. 2 and comprises one or more passages 25, 26 located in the piston 22, which are controlled by ball check valves 27 28 in the lower face of the piston and retained by a clip 29 in the enlarged ends of-the passages 25, 26. During the earlier ,part of the downward movement of the piston, pressure of the liquid in chamber 21 holds the balls against their conical seats and closes the passages 25, 26. When the door is almost wholly checked, however, the pressure in chamber 21 has so lowered that the balls drop downward of their own weight and open up the additional passages 25, 26 so that additional power of the spring 10 may be applied to latch the door. When the door is opened, -a movement reverse of that described takes place, andin this case, the

liquid, flowing into the pressure chamber,

opens the check valves 27 28 as soon as the door begins the opening movement.

' One of the most serious objections to neral character in which a liquid is emp oyed as a governing medium is theliability to leakage owing to pressure generated during the checking 'movement, and another reasons. This defeet has been remedied the present in'-* vention by the provision of two chambers coiitainin the, liquid, designated respectively as t e pressure chamber and the overflow chamber, In the construction .shown and the modeof -o eration described, the greatest pressure 0 the liqui'd Occursin chamber 21 which is completely inclosed by .artition 20, piston 22, and cylinder. 18.

oreover should any leakage occur from this chamber, the liquid can only escape into the'overflow chamber 13, so that itis of no consequence if such leakage should occur. The overflow chamber 13 is pref chamber and equipped with ports, and a rotary piston longitudinally movable in said cylinder and adapted to control said ports.

chamber and an overflow chamber, a cylinder and a rotary and longitudinally movable bers, the cylinder being equipped with ports adapted to be controlled bythe movement of the piston.

tition separating the easing into a pressure chamber and anoverflow chamber, a cylinder and a rotary and longitudinally movable piston located intermediate the two chambers, thesaid partition being equipped with a bypass.

4. In a liquid door check, a casing, a parchamber and an overflow chamber, acylinder and a rotary and longitudinally movable bers, the cylinder being equipped with ports adaptedto be controlled bythe movement of the piston, and the saidpart-ition being equipped with a by-pass. 5. i In a liquid door check, a casing having a pressure chamber and an overflow cham- .chamber and equipped witlrports, and a tion to cause the gradual closin of the ports.

including an internally screw threaded cyl ,rinder, apiston correspondingly screw threaderably only partly filled with liquid, the

piston located intermediate the two 'cliam-' gaging. threads being reduced in cross sec-.

her, a cylinder communicating with each In a liquid door check, a casing, apart1t1onseparating the casing-into a pressure piston located intermediate the two cham- 3. In a liquid door check, a casing, a partition separating the casi'ng-intoga' pressure her, a cylindercommunicating with each rotary piston longitudinally movable 1n said 7. A spring impelled liqui door check-1 Y prising a sprlng chamber, an overflow chamcopies of this patent may be obtained for five cents .each by addressing the Commissioner or Batents,

cylinder opening ed fitted therein; means for rotatingthe piston and thereby causing it to reciprocate the cylinder, an overflow chamber, and ports 'inder, a piston correspondingly screw threaded fitted therein and having the lower ends of, the screw threads tapered,' means for rotating the piston and thereby causing it to reciprocate in the cylinder, an overflow ehamber,- and ports through the Wall of-the into the, said chamber and controlled by the piston.

9; In a liquid door check, a casing comher, and a pressure chamber, all co-axially arranged, a cylinder concentric with and connecting the said overflow and pressure chambers and having internal threads, a a

threaded piston coactin'g with the cylinder, a spring in said spring chamber, a shaft rotatively driven by thespring and a slid-- ing driving-connection bet lween'the piston andshaft, and ports connecting the overflow and pressure chambers and controlled by the piston.

In testlr'nony whereof, I have hereunto subscribed my'name.

* THOMAS MOONEY.

Witnesses:

S. 'A. STORY, M. L; SMITH;

Washington, D. 0. 

